Attached is an FDK feature file for Minion Pro (2004 revision). The same code should be informative for FontLab and other applications that use the Adobe OpenType feature language.

NOTE: This should only be used as a reference for feature construction, and not for glyph names. The feature file uses "friendly names" which are often changed for final font output.

The main advantage of looking at the original feature file rather than decompiling in FontLab is that any glyph classes retain their original names. FontLab does an amazing job of decompiling features, but it has to invent names for glyph classes, and these are generally less clear than what was originally used in development.

Additionally, this feature file represents the very latest, not-even-released-yet revision to Minion Pro. So it shows our most current thinking in various areas, which may be instructive. Even once this version is shipping, not all users will have it.

If you own a copy of Minion Pro Regular (which ships with many Adobe CS applications or can be purchased separately), you can open the font in FontLab, and then import Adobe's original OpenType Feature Definition file using the OpenType panel. This will replace the .fea code decompiled by FontLab with the original Adobe code. Using this code, you can have a "behind the scenes" look at OpenType font development at Adobe. You may use it as reference for "state of the art" OpenType font development. Of course, you can look at the Minion Pro feature definition code even without owning the actual font. Thanks to the guys at Adobe for making this available!

Note that Fontlab Ltd. offers a complete OpenType font that can be used for reference (FreeFont Pro): http://www.pyrus.com/downloads/freefontpro.zip

The current version of FreeFont Pro is usable, but we at Fontlab Ltd. are working on an updated version that better reflects glyph naming and feature definition recommendations.

Microsoft offers two reference OpenType fonts (for Indic and Arabic) as part of the Microsoft VOLT package: http://groups.msn.com/MicrosoftVOLTuserscommunity

The feature definitions of Mangal Indic and Arabic Typesetting cannot be directly used in FontLab. We recommend developers who create Arabic or Indic OpenType fonts to draw the glyphs and prepare the final font without features in FontLab, and then add the features in Microsoft VOLT.

The main advantage of looking at the original feature file rather than decompiling in FontLab is that any glyph classes retain their original names. FontLab does an amazing job of decompiling features, but it has to invent names for glyph classes, and these are generally less clear than what was originally used in development.

Additionally, this feature file represents the very latest, not-even-released-yet revision to Minion Pro. So it shows our most current thinking in various areas, which may be instructive. Even once this version is shipping, not all users will have it.